The objective of the UXO survey and ID & clearance campaign is to mitigate the risk of unexploded ordnance (UXO) present in the cable installation corridor(s) to ensure a safe installation including all route clearance and route preparation activities as for example boulder clearance, Pre-Lay Grapnel run, dredging, mattress installa-tion and anchoring.
The UXO survey, as described in this document, does not comprise the onshore section.
At the shore approach, Contractor shall extend the survey and ID&C works until 0m water depth.
The scope of the UXO survey and ID & investigation clearance campaign consists of 2 phases:
Phase 1:
- High resolution bathymetry, acquired with multibeam echosounder (MBES) equipment
- Sea bottom imagery, acquired with side-scan sonar (SSS) equipment
- Magneto metric survey data, acquired with underwater magnetometer detection equipment
- Analysis based on survey investigation and interpretation of all the acquired data.
- Provision of an Master Target List (MTL), live document
- Phase 1 is to be understood as an iterative process, therefore first results can be communicated to start phase 2, while remaining works of phase 1 still need to be executed.
- Provision of a Boulder Target List
Phase 2:
- Target inspection as per master target list, identification of non-UXO items (e.g. debris) and actual UXO objects
- Electromagnetic survey, acquired with underwater electromagnetic detection equipment
- Disposal as required of both non-UXO (e.g. debris) and actual UXO objects
- Iterative updating of the master target list
- Issue of a FFE certificate (either 1 for the entire route or several per route section).